High bulky and crimpy fibrous material



April 14, 1970 sADAYuKl oKADA ET AL ',5,`5-05802y HIGH BULKY AND CRIMPY FIBROUS MATERIAL 4 Filed Feb. 24, 196'?v United States Patent Office 3,505,802 Patented Apr. 14, 1970 U.S. CL 57-156 16 Claims ABSTRACT OF THE DISCLOSURE A process for producing wool ber material having a high crimp potential and a high bulk by preventing the slippage between the bers during their stretching. The ber slippage is avoided by temperarily twisting the ber bundle prior to its stretching and setting operation and subsequently releasing the twist on the stretched and set bundle of bers.

The present invention relates to a process for treating various bers to increase their bulk and crimp properties and more particularly to a process for improving such properties during the stretching and setting of the bers.

In general, in synthetic bers, especially the acryl series of synthetic bers, it is well known to use the latent shrinkage or shrinkage potential characteristic of the ber material to produce desirable products. The shrinkage potential is obtained by suitably tensioning the synthetic bers thereby obtaining a false set hereupon the bers shrink very much upon a subsequent heating.

On the other hand, the various short bers, especially the keratinous wool bers (usually having a length of about 1-20 cm.) are inherently more diflicult, from the industrial point of view, to deal with in this respect. The same techniques as used with synthetic bers do not effect the desired shrinkage potential and crimp potential when applied to wool bers.

An object of the present invention is to provide a process for manufacturing brous products having acceptable properties which lends the brous products suitable for commercial use.

Another object of the present invention is to provide a simple and inexpensive process for treating bers which provide them with excellent elasticity, texture, tactile impression, lightness, and strength.

It is known in the art that when many short bers are arranged longitudinally to form sliver. the individual bers are partially held in place due to friction developed between adjoining bers. The normal processes employ a twisting of the sliver and while the sliver is in the twisted condition, itis stretched under tension and heated. After the stretching and setting operations, the sliver is then untwisted whereupon stretched bers are obtained. It has been found that when short bers are arranged in the axial direction along the sliver and the sliver is twisted, the bers are held by increased friction between each `other and are easily stretched.

But unlike synthetic bers, the setting property of the wool bers is greatly affected by moisture, time and other factors. Moreover, the keratinous bers have a complicated molecular structure which makes it difcult to obtain distinct operating parameters as compared to the synthetic bers.

The present invention attempts to solve these problems by imparting a temporary twist to the keratinous fibers to take up the slack between the bers prior to the stretching and setting operation. The bers are then set and stretched while in a state of temporary twisting so that no slippage between adjacent bers occurs; after the setting operation, the temporary twist is released. According to this invention, textile products such as improved yarn, knitted cloth, woven or non-woven cloth, articles of clothing and other products can be manufactured from the ber material of this invention. The textile products or the ber material itself can be manufactured into underwear, socks, gloves, upper garments, mufers, headgear, ornaments, handicraft material, toys, cushion material, carpets, wall material, chair covering material, footwear material and other articles having suitable elasticity and tactile properties.

In the following detailed description, the set means that necessary set, which is known in the art, which should be applied to the particular ber material under consideration. The term temporary set means the set such that the shape and dimension of the ber material may be changed according to a subsequent relaxation treatment whereas the term permanent set means the set such that no change or only a slight change in shape and dimension subsequently occur.

Other objects and advantages of the present invention will become apparent from a reading of the following disclosure when taken in conjunction with the attached drawings wherein:

FIG. 1 is a side view of a two-ply sliver wherein the particular ber direction is the same as the longitudinal direction of the sliver;

FIG. 2 is a side view of a two-ply sliver wherein the ber direction is the same as the twist direction of the sliver itself;

FIG. 3 is a graph showing the percentage of shrinkage of a single twist sliver in water at C.;

FIG. 4 is a graph showing the percentage of shrinkage of a two-ply or multi-ply sliver in water at 100 C.;

FIG. 5a is an explanatory view of a wool ber material having the desired crimp potential according to the present invention;

FIG. 5b is an explanatory view of the crimped ber material shown in FIG. 5a subsequent to a relaxation treatment; and

FIG. 5c is an explanatory view of a conventional, crimped wool ber material which is produced not in accordance with the present invention.

The invention will now be described with reference to the above-mentioned drawing and the following process ow chart:

(B) I (C) (A) (D) l Raw Material I-I Twisting l-Ietreatment Stretching and setting (temporary (E) (F) gor permanent Untwistiug Drying m i-*i without Stretching I l (F) (E') Drying Untwisting With Stretching (A) RAW MATERIAL l of the sliver to the fibers on the outer, peripheral portion 3 (B) TWISTINGV The sliver-shaped bundle is then subjected to a twisting operation primarily for the purpose of preventing slip between neighboring fibers in the sliver bundle. The twisting operation is a temporary operation, i.e. it is subsequently followed by an untwisting operation, and the purpose of the twisting operation is to avoid the slippage which would otherwise occur between the fibers when the bundle 'is later stretched. In general, the degree of twisting is dependent upon the subsequent degree of stretching, the manner of twisting, the kind of fibers being used, and their length and frictional coefficient. By way of example, a typical wool sliver of 2O g./m. was twisted in the range of about 0.05-0.4 turn/ cm. whereas a wool sliver of 5 g./m. was twisted in the order of about 0.4-1.0 turn/ cm.

In carrying out the twisting operation, it is not necessary to twist the fiber bundle to such a degree that all of the fibers in the sliver do not slip, the desirable results of the present invention may still be realized provided that a minimum ratio of the number of fibers which do not slip to the total number of fibers be maintained. The desired ratio can be obtained by twisting the fiber bundle such that a part of the fibers are allowed to slip, then stretching and setting the twisted fi-ber bundle, and then untwisting the fiber bundle thereby providing a mixture of stretched and unstretched fibers which have the desired shrinkage potential and crimp potential. In this way, fibers in both the stretched and unstretched states are produced at the same time, thus the mixing operation of the stretched fibers and the unstretched fiber-s is facilitated and the uniform mixing of them can be easily attained. Various twistingoperations are classified as a single twist sliver, a two-ply sliver and a multi-ply sliver and examples of each technique will now be given.

In the single twist sliver operation, as the sliver is progressively twisted and stretched, the fibers lying near the center, longitudinal axis of the twisted sliver undergo the same degree of stretching as the stretching rate given to the sliver, but the stretching rate of the fibers becomes proportionally smaller than the sliver stretching rate the farther out the fibers are from the center longitudinal axis of the sliver. Near the outer periphery of the sliver, the fibers are most susceptible to slippage. The thus twisted sliver is then subjected to a stretching and setting treatment and is subsequently untwisted whereupon the resulting sliver includes fibers having various degrees of twist including some fibers having the same stretching rate as the stretching rate of the sliver to those fibers having nearly no stretch.

In the two-ply and multi-ply sliver operations, there is less chance that fiber slippage will occur than in the single twist sliver operation. Accordingly, when fiber slippage is not needed, the two-ply or multi-ply system is preferable. FIG. 1 shows a two-ply or multi-ply sliver wherein the direction of the first twist is the reverse of the direction of the final twist whereupon the axial directtion of the twisted sliver is the same as the direction of the fibers 1a. If the first twist is represented by T turns/ cm., nthen the final twist is determined by the expression T/\/n turns/cm. wherein n is the number of slivers regularly arranged and as shown in FIG. l, rz equals 2. If the final twist is applied in the reverse direction as the first twist, and the final bundle is then stretched, set and then untwisted, thestretching rate of the fibers will then very nearly equal the stretching rate of the sliver.

' FIG. 2 discloses a two-ply sliver wherein a first twist of T turns/cm. is applied in one direction, the same twist -is then applied in the reverse direction, and then an additlonal twist of T turns/ cm. is applied in the first direction. In'this example, the fibers 1b are in an untwisted state relative to each sliver so that when the two-ply sliver is stretched and treated, the stretching rate of the fibers decreases from those fibers on the center, longitudinal axis of the sliver by an amount corresponding to the twisting angle of the sliver, much in the same manner as occurs in the case of the single sliver twisting operation. In the FIG. 2 example, it has been foundthat each sliver contains a uniformly distributed arrangement of fibers including an arrangement of fibers from ones havingnearly thev same stretching rate as the -stretching rate of the sliver to those fibers having a stretching rate proportionally decreased by an amount corresponding-to the twist angle of the sliver.

Other twist numbers can be used in practicing the present invention and for example a first twist of T turns/ cm. is applied in one direction and a final twist of T/ n turns/ cm. is applied in the reverse direction, the fibers will become distributed spirally around the center, longitudinal axis of the twisted sliver so that the fibers are subjected to various stretching rates along their axial direction.

FIGS. 3 and 4 show the distribution of the temporary set obtained in the case of the single sliver twist and twoply sliver twist, respectively.

(C) PRETREATM'ENT The twisted sliver is then subjected to a bath treatment. The bath treatment may comprise immersing the fibers in a bath, or showering the fibers, or subjecting the fibers to a fog atmosphere. Bath treatments per se are well known and condition the fibers so that they may be smoothly stretched. The permeation of the bath into the inner portion of the sliver occurs very rapidly, usually in the order of about 5-10 seconds.

(D) STRETCHING AND SETTING The pretreated sliver is then subjected to a stretching andsetting operation. Either a temporary set or a permanent set may be employed and are preferably performed in a bath. The composition of this bath may comprlse water contained in a permeating agent, various chemical agents such as diluted aqueous solutions of alkali and acids, setting agents such as diluted thioglycolate and sodium sulfite, and in addition various materials such as oxidizing, reducing, radio active, electromagnetic, etc.,

can be employed depending upon the degree of set required. The permeating'agent may be mixed with volatile alcohol to facilitate the permeation and stretching and the pH may be adjusted to about 4-9.

The bath temperature and immersion time vary with the type of treating bath being used, the concentration of the treating bath, the extent of stretching, whether the set is to be temporary or permanent, the degree of set, etc. From experimentation, it has been found advantageous to subject the pretreated fibers to a temperature of between 50-100 C. for between 10 minutes lto an hour so that the treated fibers hold their stability during later processing or storing in the factory. The setting operation -is closely related to the untwisting and drying operations, as will be fully described below, and the slivers are wound by any conventional method, such'as the batch method. Any conventional stretching method which effects `a uniform stretching maybe employed, such as the stepped stretching method which comprises stretching-'relaxationstretching steps. v

(E) UNTWISTING Upon completion of the stretching and setting treatment, the slivers are subjected to an untwisting process. The fibers may be cooled by means of cooling water, etc., prior to the untwisting operation.

(F) DRYING WITHOUT STRETCHING In the alternative, the slivers which have been stretched and set may then be subjected to a drying with stretching operation following by an untwisting operation and conventional stretch drying techniques may be used. Likewise, if a permanent set is desired, the temperature should be reasonably high and should preferably exceed 100 C. Thepresent invention is characterized in that the fibers are temporarily twisted to avoid slippage therebetween during the subsequent stretching operation, then stretching. and setting the temporarily twisted fibers and then either untwisting and drying the fibers without stretching or drying the fibers with stretching and then untwisting the fibers. The various conditions of the fibers, as they undergo the various process steps of the present invention may be seen in FIGS. cl-56. In FIG. 5a, the fibers 2 are illustrative of the fibers which have undergone a stretching, temporary setting, and drying without stretching operations and the fibers 2 consequently possess the desired shrinkage potential and crimp potential. If the fibers 2 are then subjected to a relaxation treatment and the temporary set is released, the fibers accordingly shrink and assume the shape of the fiber 3 shown in FIG. 5b. The fiber 3 is sufficiently crimped and possesses good appearance and tactile properties. In contrast FIG. 5c shows a wool fiber 4 which has not been treated according to the present invention and it can be seen that the fiber 4 has an uneven crimp.

Fibers subjected to the treatment of the present invention may be mixed with untreated fibers having a low shrinking potential and the resulting mixed fiber bundle may be subjected to a relaxation treatment, such as a heat treatment. The fibersV which have the low shrinking potential will then swell out due to the shrinking of the fibers resulting in a fiber bundle having ya varying bulkiness and curling. The variably crimped and bulked fiber bundle .posseses good texture and a fine appearance and suitable wrinkle-proof articles can be manufactured therefrom.

In the temporary setting operation, as described above, the fibers which are subjected to the stretching with drying operation lie in the sliver bundle in a very nearly straight condition and when the fibers are later subjected to a relaxation treatment, a fine crimp and a suitable bulkiness is obtained. The slivers may then be woven or knitted and thereafter subjected' to another relaxation treatment if desired. By such a treatment, high bulk, suitable curling, varied crimp and neness, fine external appearance, good tactile impression, lightness, etc. can all be obtained. y

In practicing the present invention, the stretching and setting treatment of the fibers may occur at the same time or the setting treatment may occur after the stretching operaion. Likewise, the drying operation can be applied when the fibers are in a twisted state or after an untwisted operation, and the drying operation can also be applied with or -without a stretching of the fibers. The degree of setting determines the shrinkage potential, the fineness of the ber, the crimp variation, etc. and by employing fiber materials have different properties, various fiber products may be obtained. In other words, the

keratinous Vfibers maybe combined in a suitable ratio with other natural or synthetic fibers to produce yarns, etc. having different properties.

The following examples will more clearly point out the present invention and the manner of practicing same.

Example 1 A single sliver of wool fibers was temporarily twisted and pretreated, then the fibers were subjected to a stretchinggand temporary settin'g operation, and thereafter the fibers were stretch dried. The wool sliver had a size of 30 g./m. and was subjected to an S twisting of about 0.1 turn/cm. The fibers were kept in a stretched condition during the setting treatment which was at 75 C. for 20 minutes and thereafter the sliver was dried at 60 C. for 90 minutes while kept in its twisted condition and then the sliver was untwisted. The fibers thus obtained were in a strained condition but exhibited the same crimp potential as the bers in Example l. The sliver was then subjected to a boiling water relaxation treatment and the rate of shrinkage of fibers had a mean value of 19% as shown in FIG. 3.

Example 3 A two-ply sliver wool fibers having a size of about 15 g./1n. was subjected to a Z twist having a first twist of 0.25 turn/cm. and a final S twist of 0.13 turn/cm. The two-ply sliver was stretched 20% in a 2% aqueous solution of monoethanol amine bi-sulfate at C. and then subjected to a permanent set treatment for 40 minutes after which the two-ply sliver was washed with water and untwisted and finally dried. The fibers thus obtained had a somewhat stretched crimp but had a crimp potential capable of presenting a fine and uniform crimp after completion of the relaxation treatment, but the fibers -would hardly shrink even in boiling water.

Example 4 -The same two-ply sliver of wool fibers was processed the same as in Example 3 except that the drying operation was carried out with stretching. The fibers had substantially no crimp but had a remarkable crimp potential. The fibers thus obtained were spun into yarn and subjected to a relaxation treatment in water at about 40 C. and the resultant yarn product was quite soft and the fibers exhibited a very fine crimp, as shown in FIG. 5b.

Example 5 In this example, the Wool sliver underwent the same treatment as in Example 1 up to the relaxation treatment. Instead of the relaxation treatment given in Example 1, 50% of the treated wool sliver was mixed with 50% of untreated wool sliver. The treated wool was hosiery yarn (2/ 36) spun by the usual method and the untreated wool was hosiery yarn (2/32) obtained by spinning in the usual method. The mixture ofA treated and untreated wool was then subjected to a shrinkage treatment whereby the same number of meshes per unit area was obtained. In vthis example, the shrinkage treatment consisted lof a steam heating operation which caused the untreated Wool fibers to swell out due to their shrinkage resulting in a hosiery product high in bulk and having excellent texture and tactile properties. l

l Example 6 In this example, a textile was made from a conventional mixed spinning operation. The textile comprised 25% of wool fibers obtainedrby the method of Example 2, 25% untreated wool fibers, and 50% synthetic fibers (for example, polyester fibers). The textile Was made by using the woven yarn spun by the usual method and the resulting textile exhibited excellent texture and had a much superior wrinkle-proof property than did a similar textile having 25 of contract yarn rather than the 25 wool fibers obtained by the method of Example 2. In addition,

7 the resulting textile product exhibited suitable qualities such as softness, fullness, and stiffness.

Example 7 This example is similar to Example 1 except that the fibers are acryl fibers rather than wool fibers. In this example, the acryl fibers were stretched by 20% in water at 70 C. after undergoing a twisting operation, the acryl fibers were then cooled in cold water, then untwisted and finally dried in hot air at 40 C. The rate of shrinkage of the fibers thus obtained had a mean value of 13%.

Example 8 This example is similar to Example 1 except that a false twist was applied to the fibers prior to the stretching and setting operation. The false twist was applied so that the final, released condition of twist can be obtained without the necessity of employing an untwisting operation after the stretching and setting operations.

According to the present invention, short fibers, especially keratinous fibers, are provided with excellent elasticity, texture, tactile impression, lightness, strength and other desired properties. The products made from such fibers will exhibit high bulk, special texture, heat insulating properties, lightness, and wrinkle-proof properties, all of which are attributed to the present invention and which can be produced easily and economically.

What we claim and desire to secure by Letters Patent is:

1. A process for the production of units of fibrous material comprising the steps of twisting, temporarily, a sliver-shaped bundle of short keratinous fibers such as wool to avoid the slippage which would occur between the fibers when the bundle is stretched, stretching said twisted bundle of short keratinous fibers and finally setting the stretched bundle of short keratinous fibers.

2. The process of claim 1, wherein said setting is a temporary set.

3. The process of claim 1, wherein said setting is a permanent set.

4. The process of claim 1, wherein the twist applied to the bundle of short keratinous fibers by said twisting step is released after the setting step.

5. The process of claim 4, wherein the fibers are dried without stretching after the step of releasing the twist applied to the bundle of short keratinous fibers.

6. The process of claim 4, wherein the short keratinous fibers are dried with stretching before the step of releasing the twist applied to the bundle of short keratinous fibers.

7. The process of claim 1, wherein during the stretching step the fiber is exposed to a setting medium.

8. A process for the production of units of fibrous material comprising the steps of twisting, temporarily, a plurality of sliver-shaped bundles of short keratinous fibers such as wool to avoid the slippage which would occur between the fibers when the bundles are stretched, stretching said twisted bundles of short keratinous fibers and setting the stretched bundles of short keratinous fibers, said twisting step including; applying a predetermined number of twists to each bundle, applying a few bundles together, applying a predetermined direction to the twists, and combining the applying steps in different sequences.

9. The process of claim 8 including applying a first twist to the sliver-shaped bundles of short keratinous fibers, and applying the final twist to said arranged plurality of fibrous bundles in the reverse direction to said first twist to dispose each fiber so that the fibers may be directed in the axial direction of the whole mass formed as one body.

10. The process of claim 8 including applying a first twist to the sliver-shaped bundles of short keratinous fibers, and applying the final twist to said arranged plurality of fibrous bundles in the reverse direction to said first twist to dispose each fiber so that the fibers may be directed in the direction of twist of the whole mass formed a-s one body.

11. The process according to claim 8, wherein said fibrous material is yarn.

12. A process for the production of units of fibrous material having a high bulk and crimpy potential comprising the steps of twisting, temporarily, a sliver-shaped bundle of short keratinous fibers such as wool to avoid the slippage which would occur between the fibers when the bundle is stretched, stretching and setting the stretched bundle of short keratinous fibers, drying and stretching the bundle of short keratinous fibers, releasing the twist applied to said bundle, mixing said fibrous units with fibrous material having a low shrinkage potential, placing mixed fibrous materials in a restrained state at the point where the fibers of said mixed fibrous materials cross one another, and finally subjecting the restrained fibrous material to a treatment which induces shrinkage and crimp of the fibrous material, whereby the fibrous material having low shrinkage potential expands due to the shrinking of the fibrous material having a higher n shrinkage potential and crimp potential than the material having a low shrinkage potential, thereby bringing out the crimp in said fibrous units and imparting bulk and crimp to the material of mixed fibrous materials.

13. The process of claim 12, wherein said fibrous material is yarn.

14. A process for the production of units of fibrous material having a high bulk and crimp potential, comprising the steps of applying a first twist to a sliver-shaped bundle of short keratinous fibers, applying a final twist to a two-ply arrangement of said sliver bundles or a multiply arrangement of said sliver bundles, stretching the reverse twisted bundles simultaneously with the application of a treating medium such as water, drying the stretched bundles with stretching, releasing the bundles twist, thus providing fibrous material having a high crimp potential, spinning said fibrous material, and finally subjecting the spun yarn to a treatment which induces a crimp in the fibers.

15. The process of claim 14, wherein said fibrous material is yarn.

16. A process for the production of units of fibrous material comprising the steps of twisting, temporarily, a sliver-shaped bundle of short keratinous fibers such as Wool to avoid the slippage which would occur between the fibers when the bundle is stretched and then stretching said twisted bundle of short keratinous fibers.

References Cited UNITED STATES PATENTS 2,575,753 1 1/ 1951 Foster. 3,146,574 9/ 1964 Earnshaw 57-140 3,151,439 10/1964 Dusenburg 57-156 XR 3,330,896 7/1967 Fujita et al 57-140 XR 3,353,345 11/1967 Setzer 57-140 FOREIGN PATENTS 985,621 3/ 1965 Great Britain. 1,074,681 7/ 1967 Great Britain.

6401481 8/ 1964 Netherlands.

DONALD E. WATKINS, Primary Examiner 

